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Mesozoic subduction-accretion zone in northeastern South china Sea inferred from geophysical interpretations

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Science china Earth Sciences 2006年第5期49卷 471-482页

作者： ZHOU Di1, WANG Wanyin2, WANG Jialin3. PANG Xiong4, CAI Dongsheng5 & SUN Zhen1 1. Key laboratory of Marginal Sea geology, South china Sea Institute of Oceanology, Chinese Academy of Sciences, Guang- zhou 5103.1, china 2. College of Geological and Topographical Engineering, Chang’an university, Xi’an 710054, china 3. Key laboratory of marine geology, tongji university, shanghai 2.0092. china 4. china National Offshore Oil Co. Limited – Shenzhen Branch, Shenzhen 518067, china 5. china National Offshore Oil Co. Limited – Research Center, Beijing 100027, china 1. Key laboratory of Marginal Sea geology South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China 2. College of Geological and Topographical Engineering Chang’an University Xi’an 710054 China 3. Key laboratory of marine geology Tongji University Shanghai 200092 China 4. china National Offshore Oil Co. Limited — Shenzhen Branch Shenzhen 518067 China 5. china National Offshore Oil Co. Limited — Research Center Beijing 100027 China

A segment of Mesozoic subduction-accretion zone was inferred across thenortheastern South china Sea at approximately NE450 orientation. Basic evidence includes thefollowing: A belt of peek gross horizontal Bouguer gravity gradient (PGHGBA) is comparable in sizeand intensity to that of the Manila subduction-accretion zone. A belt of high positive magneticanomalies appears to the north and sub-parallel to the PGHGBA, representing the volcanic arcassociated to the subduction zone. The PGHGBA crosses obliquely both Cenozoic structures and presentseafloor topography, indicating a pre-Cenozoic age. The segment is offset left-laterally byNW-running strike-slip faults, in concord with the Mesozoic stress field of South china. Inaddition, the existence of the subduction zone is supported by wide-angle seismic data obtained indifferent years by different institutions. At approximate localities, a north-dipping ramp of Mohosurface is indicated by records of ocean-bottom seismometers, and a strong reflector about 8 kmbeneath the Moho reflector is indicated by both OBS and long-cable seismic records. Theidentification of a segment of Mesozoic subduction zone in NE South china Sea fills nicely the gapof the Great Late Mesozoic Circum SE Asia Subduction-acrretion Zone, which extended from Sumatra,Java, SE Kalimantan to N Palawan, and from Taiwan, Ryukyu to SW Japan.

关键词： Mesozoic, subduction zone, SE Asia, NE South china Sea, geophysics.

Lower Boundary of the marine Pleistocene in Northern Shelf of the South china Sea

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Acta Geologica Sinica(English Edition) 1991年第4期65卷 427-439,460页

作者： Wang Pinxian Xia Lunyu Wang Lujiang Cheng Xinrong Department of marine geology, tongji university, {3. 2.0092.china Research Institute, Nanhai West Oil Corporation, Zhanjiang, Guangdong 524057, china 1 1) Department of marine geology Tongji University Shanghai 200092 China 2 2) Research Institute Nanhai West Oil Corporation Zhanjiang Guangdong 524057 China

A marine stratigraphic sequence across the Pliocene / Pleistocene boundary has been found in the north-ern continental shelf of the South china Sea. The marine Quaternary deposits in the Yinggehai Basin may ex-ceed 2,000 m in thickness, probably providing the best section for studying the lower boundary of the marinePleistocene in South china. The vertical succession with planktonic foraminifers and nannofossils revealed inboreholes in the basin has been well correlated with that in the international stratotype section of thePliocene / Pleistocene boundary at Vrica, Italy, resulting in the acquirement of a biostratigraphic boundary at1.64 Ma. This boundary, however, does not coincide with any prominent lithological palaeoenvironmentalchanges in the study area and can hardly be used in geological practice. There are, in contrast, significantchanges at the level of LAD of Globorotalia multicamerata sensu lato located below the above-mentionedboundary. The percentage of planktonic foraminifers in the total population and preservation of foraminiferaltests display great changes at this level corresponding to a clear onlap on the seismic profiles and indicating adepositional hiatus at ca. 2.0-2.5 Ma. Since the level can be widely traced in the Pearl River Mouth Basin andthe Beibu Gulf Basin and well corresponds with the marked depositional environmental changes recorded inthe west Pacific and other regions, it is recommended that the Plio / Pleistocene boundary be drawn at the levelof Gr. multicamerata sensu lato LAD, roughly concurrent with the Gauss / Matuyama turn.

关键词： Lower Boundary of the marine Pleistocene in Northern Shelf of the South china Sea

Exploring cyclic changes of the ocean carbon reservoir

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Chinese Science Bulletin 2003年第23期48卷 2536-2548页

作者： WANG Pinxian, TIAN Jun, CHENG Xinrong, LIU Quanlian & XU Jian Key laboratory of marine geology, Ministry of Education, {3. Uni-versity, shanghai 2.0092. china Key laboratory of marine geology Ministry of Education Tongji University

A 5-Ma record from ODP Site 1143.has re-vealed the long-term cycles of 400—500 ka in the carbon isotope variations. The periodicity is correlatable all over the global ocean and hence indicative of low-frequency changes in the ocean carbon reservoir. As the same periodicity is also found in carbonate and eolian dust records in the tropical ocean, it may have been caused by such low-latitude proc-esses like monsoon. According to the Quaternary records from Site 1143.and elsewhere, major ice-sheet expansion and major transition in glacial cyclicity (such as the Mid-Brunhes Event and the Mid-Pleistocene Revolution ) were all pre-ceded by reorganization in the ocean carbon reservoir ex-pressed as an episode of carbon isotope maximum (d 13.max), implying the role of carbon cycling in modulating the glacial periodicity. The Quaternary glacial cycles, therefore, should no more be ascribed to the physical response to insolation changes at the Northern Hemisphere high latitudes alone; rather, they have been driven by the 揹ouble forcing? a combination of processes at both high and low latitudes, and of processes in both physical (ice-sheet) and biogeochemical (carbon cycling) realms. As the Earth is now passing through a new carbon isotope maximum, it is of vital impor-tance to understand the cyclic variations in the ocean carbon reservoir and its climate impact. The Pre-Quaternary varia-tions in carbon and oxygen isotopes are characterized by their co-variations at the 400-ka eccentricity band, but the response of d 13. and d 18O to orbital forcing in the Quater-nary became diverged with the growth of the Arctic ice-sheet. The present paper is the second summary report of ODP Leg 184 to the South china Sea.

关键词：海洋 ODP 海洋钻探工程碳循环南中国海地层学

Structural control of the Gagua “Wedge” Zone east of Taiwan Island on the southern Okinawa Trough

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Science china Earth Sciences 2005年第8期48卷 1165-1174页

作者： ZHENG Yanpeng1,2,3. LIU Baohua2,3. WU Jinlong2, LIANG Ruicai2,3. LIU Chenguang2,3.& ZHANG Zhengmin1 1. marine geology College, Ocean university of {3., Qingdao 266003. {3. 2. First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, {3. 3. Key laboratory of marine Sedimentology and Environmental geology, State Oceanic Administration, Qingdao 266061, {3. 1. marine geology College Ocean University of China 266003 Qingdao China 2. First Institute of Oceanography State Oceanic Administration 266061 Qingdao China 3. Key laboratory of marine Sedimentology and Environmental geology State Oceanic Administration 266061 Qingdao China

Based on compositive analysis and interpretation of the observed and historical data, the geophysical field characters and structural properties of the Gagua “Wedge” Zone of the sea area east of Taiwan Island and the primary tectonic stress direction and its variabilities of backarc spreading in the southern Okinawa Trough are studied. It is concluded from the study results that the Gagua “Wedge” Zone is structurally consistent with the Gagua ridge and two fault basins on both sides of the Gagua ridge, and adjusts the moving direction and distance of the western Philippine Sea plate to make the northwestward motion of the plate on its east side change to the northward subduction of the plate on its west side so that the primary tectonic stress direction of the Okinawa Trough changed from NW-SE to nearly N-S, which provided the stress source for the Okinawa Trough to enter the second spreading stage.

关键词： east of Taiwan Island, Gagua "Wedge" Zone, Okinawa Trough, structural control.

Exploring Physical Indicators for Carbonate Contents in Deep Sea Sediments

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Journal of china university of Geosciences 2003年第4期14卷 300-305页

作者： Huang Wei Liu Zhifei Chen Xiaoliang Wang Pinxian laboratory of marine geology,{3., shanghai2.0092 laboratory of marine geology Tongji University Shanghai 200092

To determine carbonate contents of deep sea sediments using physical properties is an enjoyable and efficient paleoceanographic way, which has been processed successfully in many studies based on a low resolution, but rather than a high one. A series of mathematical methods including the least square method were used in this study to build multiple regression equations between color reflectance and carbonate content, and between magnetic susceptibility and carbonate content, based on the data of color reflectance and magnetic susceptibility collected via the ODP Leg 184 cruise, as well as measured carbonate contents. We found that percent carbonate estimated with diffuse reflectance is closer to the measured one than that estimated with magnetic susceptibility, and the multiple regression equation is varied in different sites.

关键词： carbonate color reflectance magnetic susceptibility South china Sea ODP Leg 184.

Siliceous microplankton fluxes and seasonal variations in the central South china Sea during 1993.1995: monsoon climate and ? Nino responses

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Chinese Science Bulletin 2000年第23期45卷 2168-2172页

作者： WANG Rujian, LIN Jun, ZHENG Lianfu, CHEN Ronghua & CHEN Jianfanglaboratory of marine geology of MOE,{3., shanghai 2.0092. china The Key laboratory of Submarine Geoscience, State Oceanic Administration, Hangzhou 3.0012, china Correspondence should be addressed to Wang Rujian laboratory of marine geology of MOE Tongji University Shanghai China The Key laboratory of Submarine Geoscience State Oceanic Administration Hangzhou China

Seasonal variations of radiolarian and diatom fluxes in the central South china Sea during 1993.1995 were overwhelmingly controlled by monsoon climate. Radiolarian and diatom increased obviously during the Northeast (from November to February) and Southwest (from June to September) monsoons and decreased during the periods between the monsoons. The change of circulation driven by the monsoons improved water exchange in the different areas that brought rich nutrient materials for the surface microplankton, thereby enhancing radiolarian and diatom fluxes. Variation of radiolarian flux coincided with organic carbon flux, surface primary and export productivities. High radiolarian flux corresponded to high surface primary productivity. Radiolarian and diatom fluxes raised abnormally during 1994-1995 could be attributed to the El Nino event during the period.

关键词： siliceous microplankton fluxes seasonal variations monsoon climate El Nino event central South china Sea.

Impact of the closure of Indonesian seaway on climate: A numerical modeling study

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Chinese Science Bulletin 2003年第S2期48卷 88-93页

作者： YU Yongqiang, ZHOU Zuyi & ZHANG Xuehong 1. LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, china: 2. laboratory of marine {3., tongji university, shanghai 2.0092.china Chinese Acad Sci Inst Atmospher Phys LASG Beijing 100029 Peoples R China tongji Univ Lab Marine Geol Shanghai 200092 Peoples R China

Using a global OGCM and its relevant coupledocean-atmosphere GCM with the contemporary, 6 MaBPand 14 MaBP oceanic topography, respectively, a series ofnumerical experiments are implemented in order to investi-gate the effect of the north shift of Australian continent onthe tropical oceanic circulation, especially the formation ofthe western Pacific warm pool. The numerical experimentsof the individual OGCM forced by the modern atmosphericcirculation indicate that the closure of Indonesian passageresults in warming in the tropical Pacific Ocean and coolingin the tropical Indian Ocean; furthermore, it also results inchange in source of the Indonesian Through Flow (ITF) wa-ter, e.g. ITF mainly originates from the south Pacific at 14MaBP, but it mainly originates from the north Pacific *** coupled model shows similar results as the individualOGCM qualitatively.

关键词： Indonesian Through Flow (ITF) Western Pacific Warm Pool Australian Plate Paleo-oceanography.

Field measurement and analysis of turbulence coherence for Typhoon Nuri at Macao Friendship Bridge

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Science china(Technological Sciences) 2010年第10期53卷 2647-2657页

作者： SONG LiLi1, PANG JiaBin2, JIANG ChengLin3. HUANG HaoHui3.& QIN Peng3.1 Guangzhou Institute of Tropical and marine Meteorology, CMA, Guangzhou 510080, china 2 tongji university,{3. 3.Guangdong Climate Centre, Guangzhou 510080, china 1. Guangzhou Institute of Tropical and marine Meteorology CMA Guangzhou 510080 China2. Tongji University Shanghai 200092 China3. Guangdong Climate Centre Guangzhou 510080 China

For the purpose of investigating the turbulent and spatial coherent characteristics of strong wind during typhoon landing period,two 3.dimensional ultrasonic anemometer stations were set up 3. m horizontally apart on the Macao Friendship Bridge to caputure the turbulent wind velocities of Typhoon Nuri. Based on the reliable and representative field measured data,the mean wind speed and direction,turbulence intensity,turbulence integral scale,turbulence power spectra,spatial correlation coefficient and coherence function were statistically evaluated. The field measurement analysis have presented the following results: 1) Two anemometer stations provided consistent results. The mean wind speed variation in time domain presented typical M-shape curves. The strong wind (10-minute mean wind speed higher than 8th grade in Beaufort wind scale) direction changed in a big range up to 122-degrees-angle,indicating the field measurements scoped over the typhoon landing period. 2) The ratio of the longitudinal,lateral and vertical turbulence intensities of the strong wind in the typhoon eye wall region was 1:0.96:0.3.. Compared with the code defined ratio 1:0.88:0.5,the lateral component was larger and the vertical component was smaller. 3. The value of integral scale increased when the eye wall of Typhoon Nuri passed over the field measurement site. Before the center of Typhoon Nuri arrived,the integral scale of the strong typhoon wind was about twice compared with that for the non-typhoon wind. 4) The spatial correlation of the turbulent wind,coherence function curve and the decay factor had significant differences at different times during the typhoon process. In the eye wall of the typhoon,the horizontal spatial correlation was relatively strong and horizontally spatial correlation spectrum decayed slower with frequency increase. The minimum regressed coefficient C in coherence function model was 4.67,which is lower than the code defined low limit. The maximum decay factor w

关键词： typhoon field measurement and analysis turbulence characteristics coherence spectral function

CHRONOSTRATIGRAPHY,SEDIMENTATION AND EVOLUTION OF THE XIGAZE FOREARC BASIN: IMPLICATIONS FOR DYNAMIC EVOLUTION OF THE YARLUNG ZANGBO SUTURE ZONE

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地学前缘 2000年第S1期7卷 106-107页

作者： Wang Chengshan 1, Liu Zhifei 2,1 , Li Xianghui 1[WT5,5”BX](1 Institute of Sedimentary geology, Chengdu university of Technology, Chengdu 610059, china, E\|mail:wcs@*** 2 {3. of marine geology, tongji university, shanghai 2.0092

The Yarlung Zangbo Suture Zone (YZSZ), a major lineament in Tibet geological framework, which is accepted as the collision site between India and Asia (Allègre et al., 1984; Coulon et al., 1986; Dewey et al., 1990; Yin et al., 1994), is an extremely complicated tectonic zone. It includes seven different tectonic\|sedimentary units from north to south as follows: Gangdese arc complex keeping the Sangri Group inside, the Qiuwu Formation, the Giabulin Formation, the Xigaze Group, ophiolitic massifs, the Liuqu Group, and melange zones (Wang et al., 1999). Current models, which mainly focus on researches at the unit of ophiolitic massifs, propose that most of the Tethyan oceanic lithosphere was subducted into one single subduction zone active during the Middle Cretaceous or the Late Cretaceous, and closed during the Paleogene India\|Asia collision. In this report, we present latest research results on units in the Xigaze forearc basin and others in YZSZ after 6\|year\|period of comprehensive investigations. Chronostratigraphy framework, sedimentology, and evolution of the Xigaze forearc basin are discussed in details. Four thrust systems in YZSZ are named. Dynamic evolution of the YZSZ including two subductions of Tethys is presented.

关键词： submarine fan Xigaze forearc basin Yarlung Zangbo Suture Zon e